/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package com.sun.org.apache.bcel.internal.classfile;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache BCEL" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
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 *
 * 5. Products derived from this software may not be called "Apache",
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 *    prior written permission of the Apache Software Foundation.
 *
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import com.sun.org.apache.bcel.internal.Constants;
import java.io.*;

/**
 * This class is derived from <em>Attribute</em> and represents a reference
 * to a <href="http://wwwipd.ira.uka.de/~pizza/gj/">GJ</a> attribute.
 *
 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 * @see     Attribute
 */
public final class Signature extends Attribute {
    private int signature_index;

    /**
     * Initialize from another object. Note that both objects use the same
     * references (shallow copy). Use clone() for a physical copy.
     */
    public Signature(Signature c) {
        this(c.getNameIndex(), c.getLength(), c.getSignatureIndex(), c.getConstantPool());
    }

    /**
     * Construct object from file stream.
     * @param name_index Index in constant pool to CONSTANT_Utf8
     * @param length Content length in bytes
     * @param file Input stream
     * @param constant_pool Array of constants
     * @throws IOException
     */
    Signature(int name_index, int length, DataInputStream file, ConstantPool constant_pool) throws IOException {
        this(name_index, length, file.readUnsignedShort(), constant_pool);
    }

    /**
     * @param name_index Index in constant pool to CONSTANT_Utf8
     * @param length Content length in bytes
     * @param constant_pool Array of constants
     * @param Signature_index Index in constant pool to CONSTANT_Utf8
     */
    public Signature(int name_index, int length, int signature_index, ConstantPool constant_pool) {
        super(Constants.ATTR_SIGNATURE, name_index, length, constant_pool);
        this.signature_index = signature_index;
    }

    /**
     * Called by objects that are traversing the nodes of the tree implicitely
     * defined by the contents of a Java class. I.e., the hierarchy of methods,
     * fields, attributes, etc. spawns a tree of objects.
     *
     * @param v Visitor object
     */
    public void accept(Visitor v) {
        System.err.println("Visiting non-standard Signature object");
        v.visitSignature(this);
    }

    /**
     * Dump source file attribute to file stream in binary format.
     *
     * @param file Output file stream
     * @throws IOException
     */
    public final void dump(DataOutputStream file) throws IOException {
        super.dump(file);
        file.writeShort(signature_index);
    }

    /**
     * @return Index in constant pool of source file name.
     */
    public final int getSignatureIndex() {
        return signature_index;
    }

    /**
     * @param Signature_index.
     */
    public final void setSignatureIndex(int signature_index) {
        this.signature_index = signature_index;
    }

    /**
     * @return GJ signature.
     */
    public final String getSignature() {
        ConstantUtf8 c = (ConstantUtf8) constant_pool.getConstant(signature_index, Constants.CONSTANT_Utf8);
        return c.getBytes();
    }

    /**
     * Extends ByteArrayInputStream to make 'unreading' chars possible.
     */
    private static final class MyByteArrayInputStream extends ByteArrayInputStream {
        MyByteArrayInputStream(String data) {
            super(data.getBytes());
        }

        final int mark() {
            return pos;
        }

        final String getData() {
            return new String(buf);
        }

        final void reset(int p) {
            pos = p;
        }

        final void unread() {
            if (pos > 0)
                pos--;
        }
    }

    private static boolean identStart(int ch) {
        return ch == 'T' || ch == 'L';
    }

    private static boolean identPart(int ch) {
        return ch == '/' || ch == ';';
    }

    private static final void matchIdent(MyByteArrayInputStream in, StringBuffer buf) {
        int ch;

        if ((ch = in.read()) == -1)
            throw new RuntimeException("Illegal signature: " + in.getData() + " no ident, reaching EOF");

        //System.out.println("return from ident:" + (char)ch);

        if (!identStart(ch)) {
            StringBuffer buf2 = new StringBuffer();

            int count = 1;
            while (Character.isJavaIdentifierPart((char) ch)) {
                buf2.append((char) ch);
                count++;
                ch = in.read();
            }

            if (ch == ':') { // Ok, formal parameter
                in.skip("Ljava/lang/Object".length());
                buf.append(buf2);

                ch = in.read();
                in.unread();
                //System.out.println("so far:" + buf2 + ":next:" +(char)ch);
            } else {
                for (int i = 0; i < count; i++)
                    in.unread();
            }

            return;
        }

        StringBuffer buf2 = new StringBuffer();
        ch = in.read();

        do {
            buf2.append((char) ch);
            ch = in.read();
            //System.out.println("within ident:"+ (char)ch);

        } while ((ch != -1) && (Character.isJavaIdentifierPart((char) ch) || (ch == '/')));

        buf.append(buf2.toString().replace('/', '.'));

        //System.out.println("regular return ident:"+ (char)ch + ":" + buf2);

        if (ch != -1)
            in.unread();
    }

    private static final void matchGJIdent(MyByteArrayInputStream in, StringBuffer buf) {
        int ch;

        matchIdent(in, buf);

        ch = in.read();
        if ((ch == '<') || ch == '(') { // Parameterized or method
            //System.out.println("Enter <");
            buf.append((char) ch);
            matchGJIdent(in, buf);

            while (((ch = in.read()) != '>') && (ch != ')')) { // List of parameters
                if (ch == -1)
                    throw new RuntimeException("Illegal signature: " + in.getData() + " reaching EOF");

                //System.out.println("Still no >");
                buf.append(", ");
                in.unread();
                matchGJIdent(in, buf); // Recursive call
            }

            //System.out.println("Exit >");

            buf.append((char) ch);
        } else
            in.unread();

        ch = in.read();
        if (identStart(ch)) {
            in.unread();
            matchGJIdent(in, buf);
        } else if (ch == ')') {
            in.unread();
            return;
        } else if (ch != ';')
            throw new RuntimeException("Illegal signature: " + in.getData() + " read " + (char) ch);
    }

    public static String translate(String s) {
        //System.out.println("Sig:" + s);
        StringBuffer buf = new StringBuffer();

        matchGJIdent(new MyByteArrayInputStream(s), buf);

        return buf.toString();
    }

    public static final boolean isFormalParameterList(String s) {
        return s.startsWith("<") && (s.indexOf(':') > 0);
    }

    public static final boolean isActualParameterList(String s) {
        return s.startsWith("L") && s.endsWith(">;");
    }

    /**
     * @return String representation
     */
    public final String toString() {
        String s = getSignature();

        return "Signature(" + s + ")";
    }

    /**
     * @return deep copy of this attribute
     */
    public Attribute copy(ConstantPool constant_pool) {
        return (Signature) clone();
    }
}
